Cancer is a global killer of humans with breast cancer and colon cancer among the leaders with many other types killing modest amounts of humans yearly.
Two blood cancers are of interest because there is no known cure, i.e. myeloma and leukemia.
Leukemia is a type of cancer which is one of more than 100 diseases that have two important things in common. One is that certain cells in the body become abnormal. Second is that after this development, the human body keeps producing large numbers of these abnormal cells.
Leukemia is cancer of the blood cells and develops (as noted) when the human body produces large numbers of abnormal blood cells. In most types of leukemia, the abnormal cells are white blood cells. The leukemia cells usually look different from normal blood cells, and they do not function properly.
Since this cancer is complex in nature and not susceptible to any specific therapy, there are a number of treatments employed including chemotherapy when drugs are employed, biological with the use of interferon, radiation and bone marrow transplants.
Each year, nearly 27,000 adults and more than 2,000 children in the United States learn that they have leukemia for which there is no cure only palliative treatment.
The U.S. patent literature has many disclosures of heterocyclic oxo-butenoic (crotonic) compounds:                Pamukci (U.S. Pat. No. 6,232,312) describes crotonic acid derivatives (column 22, lines 43-58) for the treatment of colonic polyps;        Jones et al (U.S. Pat. No. 6,121,450) discloses crotonic acid derivatives (column 8, tine 34; column 78, line 24 and at example 34 as steroid modifiers in treating breast cancer (column 1, lines 55-58);        Kalden, et al (U.S. Pat. No. 5,334,612) discloses compounds said to be useful for treating AIDS including derivatives of carboxylic acid (column 9, line 31) and pyrrolidine (column 7, line 24);        Brown (U.S. Pat. No. 6,066,670) describes an anti-viral admixture containing crotonic acid for treating tumors (see Abstract);        Horwell, et al (U.S. Pat. No. 5,580,896) discloses many 4-oxo-2-butenoic acid derivatives (column 13, lines 21-59; also in columns 15+, examples 25,26,32,34,40,43-46,77-79,97,99,103,106,), which are useful for inhibiting colorectal cancer, i.e., colon cancer (Abstract);        Giordani, et al (U.S. Pat. No. 5,580,890) discloses 4-oxo-2-butenoic acid derivatives said to be useful for treatment of AIDS (column 1, line 8 and column 2, line 61; and,        Yonemeto, et al (U.S. Pat. No. 6,083,985) recites a number of anti-tumor or anti-AIDS agents that include butenoic acid derivatives.        
It appears from a review of the foregoing that the oxo-butenoic derivatives of interest are not disclosed and thus there is no report of their activity against human leukemia.
Consequently, there is a need for an anti-cancer drug for humans that mitigates the above mentioned disadvantages of current drug therapy and effectiveness against human leukemia.